Japan's third-largest mobile carrier said Monday it will launch a new high-speed service this week, with a portable Wi-Fi router that will support download speeds of up to 76Mbps.

Softbank said its 4G wireless network, first announced last year, will eventually support devices with speeds of up to 110Mbps, faster than many wired connections provide today.

The company will hold its official launch for "Softbank 4G" on Friday. The first device it will offer for the network will be a soap-bar sized portable Wi-Fi router from Seiko Instruments, which will allow up to 10 Wi-Fi users to share the mobile connection at download speeds of up to 76Mbps and upload speeds up to 10Mbps.

Softbank's high-speed network is based on a format called AXGP, an advanced version of an older Japanese standard, Personal Handy-phone System (PHS). Softbank has said it is "highly compatible" with TD-LTE, a Chinese standard also known as LTE TDD, which is growing in popularity throughout Asia. Media reports have said Apple will support the standard in future devices.

The service will cost &#165;5,505 (US$70) per month, or &#165;3,880 for users that also have a smartphone or tablet contract. Download speeds will be limited to 128kbps for users that exceed 5GB of data use per month, although the limit can be extended for an additional fee.

The 4G service will only be available in Japan's major cities at launch, and will revert to Softbank's existing 42Mbps network in other areas.

Japan's two other major carriers have also committed to LTE-based standards. NTT DoCoMo, the largest mobile provider in the country, launched its service in 2010 under the brand name "Xi," pronounced "Crossy."

In the U.S., Verizon and AT&T run high-speed LTE networks.

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